In general...

Select products and categories from the drop-down menus to narrow your search.

To require words

Use a plus (+) symbol before a word to find only documents containing that word. Example: Type +wildlife +bear to find documents that contain both words wildlife and bear.

To exclude words

Use a minus (-) symbol in front of words to exclude documents that contain those words. Example: Type wildlife -moose to find documents that contain the word wildlife but not moose.

Use uncommon words

Use uncommon words to retrieve documents with more focused results.

To make your search effective, click the Search By drop-down menu and select...

Phrases

Type a short phrase or question. Multi-word phrases will produce better search results. Example: To ask the question, How can I learn more about forest wildfires, type either forest wildfires or the entire sentence.

Similar Phrases

Use this technique if you do not know the exact spelling of a word or phrase or to check for synonyms or similarly spelled words. Example: A search for What do I do when my hous is in flam will find documents containing similar words or phrases such as house, mansion, residency, flame, flames, fire.

Exact Search

Use this technique to find documents that match the same pattern of words entered in the text box. Example: A search for birds of prey will find documents that contain birds prey or bird prey but not prey birds or birds capturing prey.

Complex Expression

This technique allows you to search a broader set of word extensions than word stemming (see "Word Stemming" below). Type an asterisk (*) after the initial letters of the word to cover all possible extensions. Also use (~) to specify a broader search on the following word by using synonym expansion and spelling correction. Example: A search for ~forest wild* will find documents that contain forrest or forest or woods or woodland or timberland and wildlife or wildfires.

For your information...

Word stemming

All search techniques search for different word forms such as singular, plural, or different verb tenses.
Example: Search for reflect to find documents that contain reflection, reflections, reflected, reflecting or reflects.